Simple....
so you have...

To change these fractions into improper fractions to be able to multiply...first..
Multiply the whole number*denominator..
then, add the number you got+the numerator...
and use the original denominator..as the denominator...
3*8=24
24+3=27

and...
4*3=12
12+1=13

Now, you can
multiply...

27*13=351
and
8*3=24
Thus, 
It can be converted to decimal form...
14.625
Or, mixed number form...
